In many complex systems such as digital communications systems, switching systems or “switching fabrics” are employed to route data between system modules. For example, in a network node on a digital network, a switching fabric can be used to route data packets between ports on the node, each of which, in a general bidirectional system, can serve as both an input port and an output port. The switching nature of the fabric refers to its ability to controllably route individual data packets from one of many data ports to another of the data ports.
Some switching fabrics are implemented as multiple switch “planes” or “slices”, each of which handles a portion of the total switching capability of the fabric. The switch planes are allocated in a configuration which in general permits each port to transfer data to all of the ports, including through the switching fabric back to itself. Consequently, switch planes can be extremely complex pieces hardware which can be very expensive to implement. It would therefore be beneficial to reduce the number of planes required to implement the switching a fabric.